Merged revisions 74492,74531,74545-74550,74553-74555,74588,74603,74608,74614,74616-74618,74631-74633,74652-74653,74666,74671,74737,74739,74779,74781-74782,74784,74791,74793,74818-74820,74822,74832 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/trunk

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  r74492 | r.david.murray | 2009-08-17 21:26:49 +0200 (Mo, 17 Aug 2009) | 2 lines

  Issue 6685: 'toupper' -> 'upper' in cgi doc example explanation.
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  r74531 | vinay.sajip | 2009-08-21 00:04:32 +0200 (Fr, 21 Aug 2009) | 1 line

  Added section on exceptions raised during logging.
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  r74545 | georg.brandl | 2009-08-24 19:14:29 +0200 (Mo, 24 Aug 2009) | 1 line

  #6772: mention utf-8 as utf8 alias.
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  r74546 | georg.brandl | 2009-08-24 19:20:40 +0200 (Mo, 24 Aug 2009) | 1 line

  #6725: spell "namespace" consistently.
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  r74547 | georg.brandl | 2009-08-24 19:22:05 +0200 (Mo, 24 Aug 2009) | 1 line

  #6718: fix example.
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  r74548 | georg.brandl | 2009-08-24 19:24:27 +0200 (Mo, 24 Aug 2009) | 1 line

  #6677: mention "deleting" as an alias for removing files.
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  r74549 | benjamin.peterson | 2009-08-24 19:42:36 +0200 (Mo, 24 Aug 2009) | 1 line

  fix pdf building by teaching latex the right encoding package
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  r74550 | georg.brandl | 2009-08-24 19:48:40 +0200 (Mo, 24 Aug 2009) | 1 line

  #6677: note that rmdir only removes empty directories.
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  r74553 | r.david.murray | 2009-08-27 03:04:59 +0200 (Do, 27 Aug 2009) | 2 lines

  Remove leftover text from end of sentence.
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  r74554 | georg.brandl | 2009-08-27 20:59:02 +0200 (Do, 27 Aug 2009) | 1 line

  Typo fix.
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  r74555 | georg.brandl | 2009-08-27 21:02:43 +0200 (Do, 27 Aug 2009) | 1 line

  #6787: reference fix.
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  r74588 | georg.brandl | 2009-08-30 10:35:01 +0200 (So, 30 Aug 2009) | 1 line

  #6803: fix old name.
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  r74603 | georg.brandl | 2009-08-31 08:38:29 +0200 (Mo, 31 Aug 2009) | 1 line

  other -> others where multiple arguments are accepted.
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  r74608 | senthil.kumaran | 2009-08-31 18:40:27 +0200 (Mo, 31 Aug 2009) | 3 lines

  Doc fix for the issue2637.
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  r74614 | georg.brandl | 2009-09-01 09:40:54 +0200 (Di, 01 Sep 2009) | 1 line

  #6813: better documentation for numberless string formats.
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  r74616 | georg.brandl | 2009-09-01 09:46:26 +0200 (Di, 01 Sep 2009) | 1 line

  #6808: clarification.
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  r74617 | georg.brandl | 2009-09-01 09:53:37 +0200 (Di, 01 Sep 2009) | 1 line

  #6765: hint that log(x, base) is not very sophisticated.
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  r74618 | georg.brandl | 2009-09-01 10:00:47 +0200 (Di, 01 Sep 2009) | 1 line

  #6810: add a link to the section about frame objects instead of just a description where to find it.
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  r74631 | georg.brandl | 2009-09-02 22:37:16 +0200 (Mi, 02 Sep 2009) | 1 line

  #6821: fix signature of PyBuffer_Release().
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  r74632 | georg.brandl | 2009-09-03 09:27:26 +0200 (Do, 03 Sep 2009) | 1 line

  #6828: fix wrongly highlighted blocks.
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  r74633 | georg.brandl | 2009-09-03 14:31:39 +0200 (Do, 03 Sep 2009) | 1 line

  #6757: complete the list of types that marshal can serialize.
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  r74652 | georg.brandl | 2009-09-04 13:25:37 +0200 (Fr, 04 Sep 2009) | 1 line

  #6756: add some info about the "acct" parameter.
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  r74653 | georg.brandl | 2009-09-04 13:32:18 +0200 (Fr, 04 Sep 2009) | 1 line

  #6777: dont discourage usage of Exception.args or promote usage of Exception.message.
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  r74666 | georg.brandl | 2009-09-05 11:04:09 +0200 (Sa, 05 Sep 2009) | 1 line

  #6841: remove duplicated word.
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  r74671 | georg.brandl | 2009-09-05 18:47:17 +0200 (Sa, 05 Sep 2009) | 1 line

  #6843: add link from filterwarnings to where the meaning of the arguments is covered.
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  r74737 | georg.brandl | 2009-09-09 18:49:13 +0200 (Mi, 09 Sep 2009) | 1 line

  Properly document copy and deepcopy as functions.
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  r74739 | georg.brandl | 2009-09-11 09:55:20 +0200 (Fr, 11 Sep 2009) | 1 line

  Move function back to its section.
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  r74779 | michael.foord | 2009-09-13 18:13:36 +0200 (So, 13 Sep 2009) | 1 line

  Change to tutorial wording for reading text / binary files on Windows. Issue #6301.
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  r74781 | michael.foord | 2009-09-13 18:46:19 +0200 (So, 13 Sep 2009) | 1 line

  Note that sys._getframe is not guaranteed to exist in all implementations of Python, and a corresponding note in inspect.currentframe. Issue 6712.
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  r74782 | michael.foord | 2009-09-13 19:07:46 +0200 (So, 13 Sep 2009) | 1 line

  Tutorial tweaks. Issue 6849.
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  r74784 | georg.brandl | 2009-09-13 20:15:07 +0200 (So, 13 Sep 2009) | 1 line

  Typo fix.
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  r74791 | georg.brandl | 2009-09-14 16:08:54 +0200 (Mo, 14 Sep 2009) | 1 line

  #6574: list the future features in a table.
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  r74793 | georg.brandl | 2009-09-14 16:50:47 +0200 (Mo, 14 Sep 2009) | 1 line

  #6908: fix association of hashlib hash attributes.
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  r74818 | georg.brandl | 2009-09-16 11:23:04 +0200 (Mi, 16 Sep 2009) | 1 line

  #6880: add reference to classes section in exceptions section, which comes earlier.
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  r74819 | georg.brandl | 2009-09-16 11:24:57 +0200 (Mi, 16 Sep 2009) | 1 line

  #6876: fix base class constructor invocation in example.
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  r74820 | georg.brandl | 2009-09-16 11:30:48 +0200 (Mi, 16 Sep 2009) | 1 line

  #6891: comment out dead link to Unicode article.
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  r74822 | georg.brandl | 2009-09-16 12:12:06 +0200 (Mi, 16 Sep 2009) | 1 line

  #5621: refactor description of how class/instance attributes interact on a.x=a.x+1 or augassign.
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  r74832 | georg.brandl | 2009-09-16 17:57:46 +0200 (Mi, 16 Sep 2009) | 1 line

  Rewrap long lines.
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2 files changed, 26 insertions, 13 deletions

diff --git a/Doc/reference/datamodel.rst b/Doc/reference/datamodel.rst
index 865911f..a10dbdb 100644
--- a/Doc/reference/datamodel.rst
+++ b/Doc/reference/datamodel.rst
@@ -959,6 +959,8 @@ Internal types
       If a code object represents a function, the first item in :attr:`co_consts` is
       the documentation string of the function, or ``None`` if undefined.
 
+   .. _frame-objects:
+
    Frame objects
       .. index:: object: frame
 
diff --git a/Doc/reference/simple_stmts.rst b/Doc/reference/simple_stmts.rst
index 1c7ce71..8be797c 100644
--- a/Doc/reference/simple_stmts.rst
+++ b/Doc/reference/simple_stmts.rst
@@ -151,11 +151,30 @@ Assignment of an object to a single target is recursively defined as follows.
 
 * If the target is an attribute reference: The primary expression in the
   reference is evaluated.  It should yield an object with assignable attributes;
-  if this is not the case, :exc:`TypeError` is raised.  That object is then asked
-  to assign the assigned object to the given attribute; if it cannot perform the
-  assignment, it raises an exception (usually but not necessarily
+  if this is not the case, :exc:`TypeError` is raised.  That object is then
+  asked to assign the assigned object to the given attribute; if it cannot
+  perform the assignment, it raises an exception (usually but not necessarily
   :exc:`AttributeError`).
 
+  .. _attr-target-note:
+
+  Note: If the object is a class instance and the attribute reference occurs on
+  both sides of the assignment operator, the RHS expression, ``a.x`` can access
+  either an instance attribute or (if no instance attribute exists) a class
+  attribute.  The LHS target ``a.x`` is always set as an instance attribute,
+  creating it if necessary.  Thus, the two occurrences of ``a.x`` do not
+  necessarily refer to the same attribute: if the RHS expression refers to a
+  class attribute, the LHS creates a new instance attribute as the target of the
+  assignment::
+
+     class Cls:
+         x = 3             # class variable
+     inst = Cls()
+     inst.x = inst.x + 1   # writes inst.x as 4 leaving Cls.x as 3
+
+  This description does not necessarily apply to descriptor attributes, such as
+  properties created with :func:`property`.
+
   .. index::
      pair: subscription; assignment
      object: mutable
@@ -253,16 +272,8 @@ same way as normal assignments. Similarly, with the exception of the possible
 *in-place* behavior, the binary operation performed by augmented assignment is
 the same as the normal binary operations.
 
-For targets which are attribute references, the initial value is retrieved with
-a :meth:`getattr` and the result is assigned with a :meth:`setattr`.  Notice
-that the two methods do not necessarily refer to the same variable.  When
-:meth:`getattr` refers to a class variable, :meth:`setattr` still writes to an
-instance variable. For example::
-
-   class A:
-       x = 3    # class variable
-   a = A()
-   a.x += 1     # writes a.x as 4 leaving A.x as 3
+For targets which are attribute references, the same :ref:`caveat about class
+and instance attributes <attr-target-note>` applies as for regular assignments.
 
 
 .. _assert: